WIP for email reminders

I still need to set up the tasks.
Feature [#42660023]

Added the rake task to perform the distribution of emails for the
forgetful.

Slightly modified the code handling the checkbox for the "receive
reminder" preference and checked the whole Scheduler Heroku thing.

Seems like the best it can do is daily so we'll have to test the date
inside the task itself.
tweaks
Merge pull request #83 from rescuedcode/email_reminder_actual_hours

Email reminder actual hours